The invention relates to a copper-based sliding material in which the anti-seizure property and wear resistance thereof are enhanced by evenly dispersing hard substance particles, a method of producing the same, a sliding bearing and a method of producing the same.
As a copper-based sliding material, there is a bearing in which Kelmet is used. The Kelmet bearing is used as a sliding bearing for automobile engines etc. which sliding bearing is produced by the steps of providing copper-lead-based sintered alloy layer bonded to a back metal of steel, and providing an overlay layer bonded to the surface of the copper-lead-based sintered alloy layer. In the Kelmet bearing, even in a case where the overlay layer is worn away, lead contained in the copper-lead-based sintered alloy layer is fed to the sliding surface, so that good anti-seizure property is maintained.
Namely, in conventional copper-based sliding materials represented by the Kelmet bearing, the anti-seizure property is enhanced by adding lead (of about 20 mass %). However, since lead causes bad influence on the environment, it is preferred to reduce the content of lead as little as possible or not to use any lead. On the other hand, since lead brings about the function explained above, the low content of lead makes the anti-seizure property deteriorated.